thermionic-culture Thermionic Culture The Culture Vulture Mastering Plus CultureVultureMasteringPLUSManual1

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ULTURE

TC VHE ULTURE ULTURE

mastering PLUS

OPERATING MANUAL

WARNING

Do not take this unit seriously. The Culture Vulture is a ‘fun’
effects unit and has been designed for maximum pleasure!

However, for your personal safety, please read this operating
manual and this warning thoroughly before using the equipment.

This unit must be installed in such a manner that operator access
to the mains plug is maintained. Where the product is to be rack
mounted, this may be achieved by having access to the
disconnection device for the whole rack.

To reduce the risk of electric shock, it is essential that the unit is
disconnected from the mains supply before removing the cover.

Please also note that the power supply capacitors within this unit
can remain charged even after the mains supply has been
disconnected. It is essential that these capacitors are discharged
after the mains supply has been disconnected and the covers
have been removed.

In the event that this unit has been dropped or has suffered an
impact, an electrical safety test must be carried out before
reconnection to the mains supply.

This equipment is not intended for use in explosion hazard
environments. It must be used and stored in studio conditions,
such that the ambient relative humidity does not exceed 80%, nor
is the temperature to be allowed to drop to a level, which would
cause dew point to be reached.

The Culture Vulture Mastering PLUS, though valve based, does
not run exceptionally hot. Other equipment can be mounted in the
rack directly above and below it, as long as the rack is well
ventilated and the ventilation slots are not obstructed.

©Thermionic Culture Ltd, May 2010 1

CONTENTS

Section Page
1 Introduction 3

2 Controls & Meters 4

2.1 Drive 4

2.2 Output Level 4

2.3 Bias (and meter use) 4

2.4 Function Switch 5

2.5 Filter 5

2.6 Bypass 5

3 General Operational Hints 6
4 Inputs and Outputs 7
5 Servicing and Maintenance 8

5.1 Valves 8

5.2 Operating voltage / Fuse 9

6 Specification 10

©Thermionic Culture Ltd, May 2010 2

1 Introduction

The Culture Vulture is the first and only all valve unit, dedicated
to producing the best harmonic distortion money can buy.
It can ‘warm’ a sound gently, or create a noise like a 200 watt
guitar stack overdriven with all speakers slashed.

The Culture Vulture is a two channel unit for adding harmonic
distortion to a variety of input sources. By biasing and
configuring the distortion valve (5725), four types of distortion
with infinite variations can be achieved.

Although the unit can be ‘clean’ (less than 0.2% THD), added
valve distortion may be quite desirable, improving naturality and
smoothing off unwanted digital spikes. But The Culture Vulture
can be used for effects! Push it and try it!.

The user has total control over the type and amount of
distortion, which can be changed from even to odd harmonics or
a combination of both. Starved, the sound from The Vulture
becomes thin and loses its body, overfed, it becomes fatter and
more rounded.

The Culture Vulture features two channels which can be used
independently on individual tracks, or put across a whole stereo
mix.

The CULTURE VULTURE MASTERING was developed for
mastering engineers to add subtle distortion to a mix or pair of
tracks for “warming up” the sound. The Mastering + Culture
Vulture is designed to provide accurate recallable facility plus
the ability for even more extreme distortion, so that it can be
used in all applications where valve distortion is required.

We have used a Mullard M8100 input valve to achieve very low
noise. The extra “drive” position gives some of the bite of
“overdrive” but with far less noise. The extra control over output
level with the (-10db) switch allows the unit to be driven into
extreme distortion but still have a respectable stereo balance.
However the “P2” and “P3” positions will become so extreme
that true stereo won’t always be applicable.

©Thermionic Culture Ltd, May 2010 3

2 Controls & Meters

2.1 Drive

This control is really in 2 parts, a switch and a rotary pot.
The switch gives a coarse control and the pot a fine control
of the signal input level. At the first position “Normal” (for
line level signals) the frequency response is flat. The
“Drive” position increases the gain by 10dB and adds some
top end for extra bite. “Overdrive” is 28dB above “Normal”
and can be used for extreme distortion effects at line level,
also guitars and other low level sources.

The drive pot controls the amount of signal you are feeding
to the 2

nd

valve, a 5725, so the higher it’s set the more

effect. It should be used in conjunction with

2.2 Output Level

Again this control is in 2 parts, a switch (-10dB) and a
rotary control. This controls the signal going to the output
valve. Usually set rotary control between 0 and +4 with
switch down for low distortion at line level. Set the switch to
(-10dB) and reduce the rotary control when pushing the
distortion valve at other than P3, which always requires
maximum gain

2.3 Bias (and meter use)

This control varies the current through V2 by changing the
positive voltage on its cathode. The actual current is shown
on the milliammeter. When the Vulture is starved of
current the sound is thinner and when over-fed it becomes
warmer and fatter. The best setting for low distortion is

0.25 mA. When the Vulture is being pushed into heavy

distortion the meters will twitch. N.B. The bias pot is

naturally noisy in operation as all of the valve’s current is
flowing through it, but it should be silent when set.

©Thermionic Culture Ltd, May 2010 4

2.4 Function Switch

“T” and “P1” positions mean that V2 is configured as a
triode (all even harmonics) or a pentode (odd harmonics).
“P2” is an exciting new discovery. It will sound quite clean
until overload is close when lots of harmonics are suddenly
added, and at higher levels over-compression will occur
and dynamics are inverted
“P3” is a very distorted sort of pentode. Rectifying effects
can be obtained when lowering the bias and this can result
in what sounds like pitch change to the ear.

2.5 Filter

This is a low pass filter taking out frequencies above 7 kHz
at 12dB/octave.

2.6 Bypass

This switch links the input to the output directly, cutting out
the electronics of the Culture Vulture.

©Thermionic Culture Ltd, May 2010 5

3 General Operational Hints

When just “warming” the sound use “T” or “P1” settings with
output level control at 0 or line level output. Turn down the
control as you increase input level and/or with increased V2
current settings. Turn to max for most “P2” & “P3” applications.

The “cleanest” setting for the bias is 0.25mA and “T” function,
this should be used to give sounds just a bit more “naturality”.
The unit will have unity gain at this setting when Drive & Output
level controls are set to “0”.

A good setting to simulate analogue tape distortion is “T”,
normal drive, meter set to 0.3-0.4 mA. The most popular
setting, generally, appears to be “P” 0.4mA with Output level
reduced.

On the “P2 & P3” settings only, it’s a characteristic of the type
of valve used that a frequency doubling effect can occur when
distortion sets in. This can be quite interesting and is most
likely to occur with high bias (around 0.1mA current).

Use the “drive” setting of the “drive” switch if you want a little
more “bite” or brightness. There may be sufficient gain to use
this setting for some electric guitars when DI’d, if a low bias
(high current thru V2) is used. Otherwise, use the “overdrive”
setting when DI-ing guitars
Use the “filter” switch to reduce unpleasant upper harmonics,
especially useful when using “P2 & P3” effects.

If using the unit across a stereo mix or group, then ensure that
you set it up with both meters reading the same rather than
relying on knob positions. You can only expect a properly
balanced stereo picture when the “function” switch is set to “T”

or “P1” positions. Little chance on “P2 & P3” position.

©Thermionic Culture Ltd, May 2010 6

4 Inputs & Outputs

Line inputs and outputs on the back are balanced stereo
jacks.

The (front) DI input and (back) Output Lo are also on stereo
jacks with ring to ground. The DI input has 6dB more gain than
line input. All ins and outs can be used with balanced or
unbalanced connectors.

©Thermionic Culture Ltd, May 2010 7

5 Servicing & Maintenance

5.1 Valves

The unit comes with a 12 month warranty covering all
parts, including valves, and it is essential that it is returned
to our factory or to the dealer from which it was purchased
for repairs to be carried out otherwise the warranty is
invalidated. There is, however, one important exception to
this rule:

Valves are quite delicate items and the most common
cause of failure, despite our choice of high quality military
grade ones.

If a fault occurs on one channel, a valve is quite likely to be

the cause, so if you feel confident and willing to do the
following, here’s the procedure:

Unplug the power and remove the top by undoing screws
which attach it. Note: 1 screw is shiny and must be
replaced in the same place. The unit can be powered up
safely without the top on provided that the screening plate
above the circuit board is not removed and reasonable
care is taken not to touch exposed connections, but don’t
change valves with the power on! Change over the 2 input
valves. These are the ones with metal screening cans
nearest the left & right sides. If you press down a little and
twist the can anti-clockwise it will come off, then gently pull
out the valve. Be careful when replacing that the pins line
up. Do not bend them! Plug back in and see if the fault has
changed sides, if not try changing the next pair in (the
“distortion” valve). Be sure not to mix up the valves as they
are different types and have different pin connections!

The valve in the centre is the output valve and is a double
triode common to both channels. This is very robust – we
have had to replace less than 11 in 11 years, so it’s
unlikely to be a problem in the 1
to be sure, you can replace it with the common ECC82
(12AU7) with very slightly degraded results. Spares can be
obtained from Thermionic Culture Ltd.

st

12 months. If you want

©Thermionic Culture Ltd, May 2010 8

Input valves can be replaced individually but “distortion”
valves should be replaced in matched pairs if you use the
unit for stereo. (otherwise it can be quite fun to have
different sounds from each side – some of our old
customers prefer it!)

Valve complement: (equivalents in brackets, nearest 1

Input 2 x ( M8100 ,EF95 6AK5)
Distortion 2 x 5725 ( 6AS6)
Output - 1 x 5963 (, ECC82, 12AU7)

5.2 Operating voltage / Fuse

The Culture Vulture Mastering Plus is switch
selectable to operate from either 230V or 115V 50/60Hz
AC mains supply.

NOTE: Mains fuses may be replaced in accordance with
the following table:

Operating Voltage Fuse Rating

115V T500mA 20mm type
230V T250mA 20mm type

st

)

©Thermionic Culture Ltd, May 2010 9

6 Specification

A) Figures obtained with 1kHz signal, 0.25mA bias current,

Function at T, feeding a 10kΩ load.

Distortion (THD): 0.2%
Frequency response: 40Hz to 20kHz , + 0.5/-1dB
Max Output Level (MOL): +14dBu, 2% distortion
Gain available: 47dB line, 53dB DI input
Noise: 83dB below MOL

B) Maximum Figures:

Distortion (THD): 98%
MOL: +21dBu, 20% distortion
Gain: 76dB, P1, min. bias.

C) Impedances:

Line Input: 20kΩ
DI Input: 50kΩ
Hi Output: 2kΩ
Lo Output: 4kΩ

©Thermionic Culture Ltd, May 2010 10

Thermionic Culture Ltd., Harlow, Essex, UK

Tel: [phone] Fax: [phone]

© 2010 Thermionic Culture Ltd. Printed in UK.